1. Field of the Invention
The present invention relates generally to a polyolefin composition and, more specifically, to polyethylene (PE) formulations being formed from a high clarity slip antiblock masterbatch. The inventive PE masterbatch contains a clarifying agent, a high clarity antiblock and an amide slip additive. This results in at least one of a Low Density Polyethylene (LDPE) and a Linear Low Density Polyethylene (LLDPE) article produced by either a cast, blown or molding process having an increased gloss, a reduced haze, a reduced coefficient of friction (CoF) and a reduced blocking force.
2. Description of the Prior Art
Present PE films may be formed from a masterbatch including clarifiers, antiblocks and slip agents. These masterbatches can be used to form the PE film as at least one of a LDPE and a LLDPE. Alternatively, the PE film may be formed barefoot which means there are no additives contained therein. Additionally, the masterbatches may be used to produce a high density polyethylene (HDPE) film. However, the HDPE films are not the concern of the present invention and will not be discussed further.
The use of masterbatches containing antiblocks, clarifiers and slip agents allow the manufacturer to give the resultant PE film certain desirable properties. Antiblocks are used to prevent blocking which is the adhesion of two adjacent layers of PE film. Blocking generally occurs when the distance between two adjacent layers of film is reduced such as when the films are pressed or rolled together. One result of blocking is an increased difficulty of separating two layers of film, either removing film from a roll or opening a thin guage bag. The antiblock, when combined in a PE resin, microscopically protrudes from the surface thereof. These protrusions minimize the contact of the two adjacent layers of film thus making it easier to separate these layers. Common antiblocks that are utilized in PE formulations include silica (diatomaceous earth) and talc. However, these anitblocks cause the PE film to have a reduced clarity and reduced gloss.
Slip agents are further added to masterbatches to reduce the CoF of the film formulation. Slip agents must exhibit good lubricity and also must be incompatible with polyethylene. When the slip agents are incorporated into the PE resin, they migrate to the surface and form a thin film. Common slip agents include oleamide and erucamide with the latter providing a more significant reduction in the CoF of the resulting PE film.
It is thus desirable to produce a masterbatch used in producing a PE film wherein the masterbatch significantly reduces haze, the CoF, and blocking force. It is also desirable to produce a masterbatch that results in a PE film having an increased gloss.